Carburetor



Dec. 28,1926. 1,612,320

H. D. scHRoEDER.

CARBURETOR Filed July 22. 1921 Patented Dec. 28, 1926.

vUNITED STTES i F I C E PATENT CARBURETOR.

Application led July 22, 1921.

Fig. 2 is a side elevation of the carburetor with a portion of the float chamber broken awav to show in section; Fig. 3 is a longitudinal detail sectional view ofthe carburetor being a view taken as indicated by line 3-3 on Fig. 1 showing the parts positioned as they are when the device is not in operation or is operating slowly; Fig. 4 is an enlarged view similar to a portion of Fig. 3 showing the parts as they are positioned when the device is in full operation; and Fig. 5 is a transverse sectional view of the device being a view taken as indicated by line 55 on Fig. 1.

Throughout the drawings numeral designates the body of the device which is in the forni of a Venturi tube having an outer or intake portion 11, an outlet portion 12, and a restricted or neck portion 13 between and connecting the intake portion 11 and the outlet portion 12. rlhe stationary Venturi tube, as I will hereinafter term the body, is preferably an integral or solid casting and is provided on its under side with a part 14 which forms a cover for the float chamber 15. The float chamber 15 is adapted tobe attached to a flange 16 at the periphery of the part 14 by suitable screws 17.

In accordance with the present invention the intake portion 11 of the stationary Venturi tube is formed with a plurality (preferably three) of inwardly extending ribs 18 which support a stationary tubular carrier 19. The inside diameter of the inner or main part 20 of the carrier is the same as the inside diameter ot' the neck portion 13 o the stationary Venturi tube, while the outer portion 21 or' the carrier is somewhat enlarged and is connected with the main portion 2O by a shoulder part 22. When the carrier 19 is in place with the shoulder part 22 seated against the rib shoulders 23, its inner end 25 is spaced from the neck portion 13 of Serial No. 486,666.

the'body 10 to leave a port or opening 26 between the spaces 27 in the intake portion 11 around the carrier 19, and the neck 13.

A movable tube 30 is carried by the carrier 19. The cylindrical inner or outlet part 31 of the tube 30 is slidably carried in the main portion or" the carrier 19. The outer or intake portion 32 of the tube 30 is connected with the inner portion 31 by a Venturi neck 33. A llange 34 extends radially from the end of the intake portion 32 of tube 30 and is slidably carried by the ribs 18. Movement of tube 30 inwardly in the carrier 19 is limited by the flange 34 engaging the end 36 of the enlarged portion 21 of the carrier. Outward movement of the tube 30 in the carrier is limited by the flange 34 engaging a ring 37 carried in suitable notches provided in the ribs 13. In accordance with the invention a helical spring 40 is arranged within the enlarged portion 21 of the carrier between the shoulder part 22 of the carrier and the flange 34V of the movable tube. The pitch of the spring varies between its two ends, being comparatively small at one end and large at the other. The variation in the pitch of the spring causes its resistance to increase as it is compressed. The spring 4() normally holds the tube 30 in its outermost position as illustrated in Fig. 3 and is adapted to allow it to move to its innermost position as illustrated in Fig. 4 under certain operative conditions.

The outlet portion 31 of the tube 30 extends into the neck 13 of the body 10 even when the Venturi tube is in its outer position as shown in Fig. 3. A plurality of ports 70 are formed in the outlet portion of the tube so that they will be out of register with passage 26 and passage 26 be completely closed when the tube is in its outer position as shown in Fig. 3, and will be in registerV with the passage 26when the tube is in its inner position as shown in Fig. 4. As tube 3() is moved inwardly the ports 70 come in register with the passage 26 to open communication between. the spaces 27 and the neck 13 until the passage 26 is completely open at which time the tube is at the inner end of its movement.

A tube 41 is carried by the part 14 so that it extends downwardly into the liquid fuel L in the float chamber 15. The level of liquid L in the float chamber may be regulated by a suitable float mechanism 42 as is usual in de ices of this character. A port 43 in one sigle of the tube 41 forms a communication. between the tube and a port 44 formed in the part 14,. A suitable needle valve 45 is arranged in connection with tube 41 so that the flow of liquid fuel from tube 41 to port 44 can be regulated. fr tube 46 is connected with port 44 and extends therefrom to the intake portion 32 of the stationary Venturi tube where it turns inwardly to be parallel to and concentric with both of the Venturi tubes. rEhe tube 46 extends into the movable tube 30 so that its discharge end, which is somewhat contracted to form a nozzle 50, is at the narrowest part of the Venturi neck 33 of tube 30 when the tube is in its inner position. 1n the outer position of tube 30 the nozzle projects a little further into the Venturi neck 33.

ln accordance with the invention member 60 is carried on the end portion of the tube 46, or is arranged in connection with the nozzle 50 so that it will form with the neck and intake portions of the venturi a passage-way which will direct air passing through it toward the nozzle 50 of the tube 46. The member co-operates with the venturi to vary the effective size of the intake passage through the venturi so that i is smallest when the tube 30 is out and gradually increases in size as the tube moves inwardly. ln the drawings and particularly in Figs. 3 and 4 of the drawings l show a typical shape in which the member 60 may be formed.

In accordance with the invention a cylinder is slidably carried on the lower end of tube 41 in the float chamber 15. The cylinder 70 is formed at its lower end with an intake opening .71 controlled by an upwardly opening valve 72. An inlet port 73 is provided in one side of the cylinder 70 at a point which is immediately below the end of the tube 41 when thc cylinder is in its lowermost position. lThe cylinder is adapted to be reciprocated on the lower end portion of the tube by oscillation of a shaft '.7 5 carried in part 14. rlhe connection between the shaft 75 and the cylinder .70 comprises an arm 76 fixed on shaft 75 and a connecting link 7'? connecting the outer end of the arm with the cylinder.

Preparatory to starting the engine in connection with which the present carburetor is arranged shaft 75 is oscillated to cause reciprocation of cylinder 70 on tube 41. Upon downward movement of the cylinder ball 72 lifts allowing liquid fuel from the float chamber to flow into the cylinder. Upon upward movement of the cylinder port 73 is cut off by the lower portion of tube 41 so that the fuel carried in the cylinder is forced upwardly through tube 41. After the cylinder has been reciprocated on tube 41 a few times tube 41, port 44 and tube 46 have been pumped full of liquid fuel and some liquid fuel has been sprayed into tube 30. Upon `starting the engine air is drawn through the device `in the manner indicated by the arrows in F ig. 3. rlhe air enters the intake portion 32 of tube 30, passes inwardly around the member 60, past and around the nozzle 50 and through Venturi neck 33, through the outlet portion 31 of tube 30, and then through the outlet portion 12 of the stationary Venturi tube from which it enters the manifold of the engine.

lVhen the engine is first started, or when it is operating at low speed, tube 30' is in its outer position as shown in Fig. 3 so that all of the air which enters the engine passes through it. As the speed of the engine increases the velocity of the air through tube 30 increases causing the tubeto be moved inwardly in thecarrier 19 against the resistance of spring 40. As soon as the tube starts to move inwardly the ports 70 begin to register with the passage 26, and begin to open the passage 26. lmmediately upon the passage 26 being opened, even the slightest amount, air passes through spaces 27 around the carrier and through Lneck 13 of the stationary Venturi tube. The air which flows through the spaces 27 is at a maximum velocity and minimum pressure as it passes through the. neck portion of the stationary Venturi tube. rl`he increased velocity and reduced pressure of the air from the spaces 27 at the neck 13 causes increased velocity, generally, of the air passing through tube 30. As the engine speed increases the velocity of air through Ithe device increases until tube 30 has been moved to its innermost position, as shown in Fig. 4, in which position the passage 26 is completely opened. 1t is preferred that the ports 70 be cut diagonally in the movable tube so that as the tube moves inwardly the passage 26 will open slower at the first part of the movement than at the last part of the movement. r1`he auxiliary air entering the device through the passage 26 is thoroughly and completely mixed with the vapor carrying air passing through tube 3G so that the engine is supplied with a uniform mixture of fuel and air.

Having described a preferred form of my invention, l Claim:

1. 1n a carburetor, the combination of an outer Venturi tube, a stationary cylindrical guide tube mounted concentrically within the outer Venturi tube and defining an annular air passage around it, the end of said cylindrical tube stopping somewhat short of the point of greatest constriction of the Venturi tub-e `so as to leave an air passage around the end of the cylindrical tube, an inner Venturi tube with a cylindrical exterior slidable in the guide tube, a stationary fuel nozzle locate-d in the inner Venturi tube near its point of greatest constriction,

the inner Venturi tube being adapted to be moved in a direction awa-y from the fuel nozzle by the action yof the air stream passing through that tube, and said inner Venturi tube also having ports in its wall adapted to pass the end of the guide tube when it is moved in said direction so that air from the outer Venturi tube is then admitted into said inner Venturi tube.

2. In a carburetor, the combination of an outer Venturi tube, a stationary cylindrical guide tube mounted concentrically within and spaced at all points from the outer Venturi tube and deiining an annular air passage between it and the outer Venturi tube, an inner Venturi tube with a cylindrical exterior slidable in the guide tube and being adapted to be moved in a direction toward the point of greatest constriction in the outer Venturi tube by the action of the air stream passing through the inner Venturi tube, a stationary 'fuel nozzle located in the inner Venturi tube near its point of greatest constriction, the air entry end of the inner Venturi tube having a flange, the corresponding en-d of the cylindrical guide tube having an enlargement presenting a shoulder, and a spring confined between said flange and shoulder and tending to move the inner Venturi tube in a direction away from the point of greatest constriction of the outer Venturi tube.

In witness that I claim the foregoing I Y 

